Blank (no signal) display on new ASUS Z590 motherboard
Solution 1:
I (or the people from ubuntu) solved the Problem. (note that im on debian)
I have installed linux-image-5.10.0-1019-oem (Edit: this kernel has a problem with USB audio, better install a later one like https://packages.ubuntu.com/focal/kernel/linux-image-5.10.0-1023-oem) which made the console work and resolved the black screen error. It contains a patch for this problem.
To get xorg working, i also had to update xserver-xorg-video-intel libdrm-intel1 intel-media-va-driver i965-va-driver and intel-media-va-driver and the whole xserver to debian testing.
Also, for the intel driver being used, i had to create an xorg.conf.d config file to force it. That may not be required if you have the newer version installed.
vainfo now reports no errors, my browser (vivaldi) complains that i965 does not support the card, but works fine regardless.
for reference, here are my versions:
root@cswork:~# dpkg --list | grep intel
ii intel-media-va-driver:amd64 21.1.1+dfsg1-1 amd64 VAAPI driver for the Intel GEN8+ Graphics family
ii intel-microcode 3.20210216.1~deb10u1 amd64 Processor microcode firmware for Intel CPUs
ii libdrm-intel1:amd64 2.4.104-1 amd64 Userspace interface to intel-specific kernel DRM services -- runtime
ii libintellij-annotations-java 17.0.0-1 all transitional package for libjetbrains-annotations-java
ii xserver-xorg-video-intel 2:2.99.917+git20200714-1+b1 amd64 X.Org X server -- Intel i8xx, i9xx display driver
root@cswork:~# dpkg --list | grep va-dri
ii i965-va-driver:amd64 2.4.1+dfsg1-1 amd64 VAAPI driver for Intel G45 & HD Graphics family
ii intel-media-va-driver:amd64 21.1.1+dfsg1-1 amd64 VAAPI driver for the Intel GEN8+ Graphics family
ii mesa-va-drivers:amd64 18.3.6-2+deb10u1 amd64 Mesa VA-API video acceleration drivers
ii va-driver-all:amd64 2.4.0-1 amd64 Video Acceleration (VA) API -- driver metapackage